Discharge spout for ball or tube mills



N. L. HALL.

V DISCHARGE SPOUT FOR BALL 0!? TUBE MILLS.

APPLICATION FILED AUG.2. 1920 1.359353. Patented. Feb. 22, 1921.

2 SHEETS-SHEET l- N. L. HALL.

DISCHARGE SPOUT FOR BALL 0R TUBE MILLS.

APPLICATION FILED AUG.2. 1920.

1,369,653. Patented Feb. 22,1921.

2 SHEETS-SHEET 2- 12 g/f4 16 Q L L .HaNL m fine/W NEWTON L. HALL, OF SALT LAKE CITY, UTAH,

DISCHABGE-SPOUT FOR BALL R TUBE MILLS.

Specification 01 Letters Patent.

Patented. reuse; 1921;

Applicatikin iiiea August 2, 1920. Serial No. mama To zill vhov aigi mtij comem: p Be a it know h t. NEW QN -v HA e citizen of the United States, residing at Salt Lake City, county of Salt Lake, and State a of Utah, have invented certain new and useful Improvements in Discharge spouts for! Ball or Tube Mills; and l do declare the ql w s 1 be. a full, l and'exa t d f scription of the invention such as xvill enable others' skilled in the ajrtto hichit ap; pertains to make and use the same, reference being had to the accompanying drawings and to the characters of reference marked thereon, which form a part of this specifica- 15 tion Y a invention lrelates to improvements in ball tube pebble mills, and particularly to a dischargespout to he usedtherewith p The object of th'e invention isto provide sneha spoutwhich illperinitquick and eflieient discharge W and ,NTti ch will retain Within the mill, halls broken balls, or oversize: material vvhich attempts to escape, Without the use of a screen. to Briefly, the invention coinprises a mill whose spout is located Wltlllllllhe trunnion onthe discharge side, said spout being provided its ifinersurlecq ah vanes or rihs preferably arm gee in series which vanes so are in the form of int erriipted=. threads Ij spirals. T e sprang of the e egant wal s prevents the giradient ofthe load from beiiiirraised ahove 'the hottorn of thespout; fili ree-Berg in mining p ance, it has at been, the Queenietonsemse nm: wer

le wahin aemia lg' r ip esien l nen;

ibfl f Y e h, cons ruct nthedraw a' z k 1 ,n a Fi 1 salonei dinelwee reeen through a mill equipped with the piesentim vention.

nates' the necessity for Fig. 2 is a similar section throngh the spout, showing the same on a larger scale than in Fig .This section is also indicated hy line of Fig. 3;

ri e; is a new eta View etaears fine" ca -'3 of Fig. 2.

Fig 4 is a rear end view of a modified m f p u -H. a,

Fig; 5 is a vertical, longitudinal section taken on line 5-- 5 of Fig,j l. V e

Fig. 6 is a rear end view of a further difi di r ig. 7 is a longitudinal section taken from line 7 7 of Fig. 6. 1 V

The shell of the mill is shownat, l andis provided withmill heads 2', andtrunnion s 52, the trunnions being hollow as indicated. The mill is provided with bearings 3 for the trunnions, a drive gear 9v ona head 2, head linerslandshell liners 5, and, a feed spout 6 is mounted Within one of the trunnions, this being provided with an internal screw 66 and heing fed by a chute 7. A'discharge 70 spout 8 is mounted withinthe opposite trunnion, being bolted thereto by means of itsfia'nge 18 and bolts 19. In the forms of discharge spout shown in Figs. 1 to 5, the vanes are arranged in two series,,the vane s 10, 12, 14 and 16 forming one series;.,anol vanes 11, 13,, 15 and 17 forming the other series,;,These vanes are preferably tilted or inclined inwardly toward the mill as shown to provide a sort ofpocket on the mill side' of each vane at the base of the vane, hrn eloy the pulp will tend topocket, and thereb y eliminate some of the Wear. As Wear takes place the free edges are gradu ally orn to present a surface nore normal 86 to the advancing matrial. If the vane were uprighgthe ear on,the free edge would soon present; a rounding, sloping surface, whichwould detract from theefficiency of the vanes. The various; vanes 10 to 17 90 gradually increase in height, as" shoWn,.. so that achsnceessiye vanetendsto ,cause sub:

' mergei oeofthe preeedingvane andthereby,

produeingwfl variableclassification of the load as well as making an effectiveohstruc; tion to the splashof the mill, and ,to too, rapid advance of tlie mill discharge. The spacing of the vanesleaves avenues between. the same for the pasfsage of the discharging niaterial which is-the finematerial. .7

In the form of Figs 6 and 7, the vanes are arranged in four series, and the innermost wall, tapers graduallyto the inner surface of the spout. Thevanes ,are; ;not arrangedfin a continuous spiral position, but, 105

e are" staggered so that a succeeding vane in in the-order given, and are of such pitch that they will tend to move the load toward the'feed end of the spout to retain balls and over-size, while the vane 27 at the mouth of the spout has an opposite pitch to assist in the discharge and thereby quickly clear the outer end of thespout. The position of the vane 27 in Fig. 7 may be in line with the space existing between the vane series,

"thereby preventing too rapid advance or discharge splash of the discharging material, or it may be in line with the vane series, but in either case its pitch is so adjusted as to facilitate clearing and discharge of the load.

In operation, referring to Figs. 1 to 5, the spout revolves with the mill and as the mill is loaded to the discharge point, the pulp or mill load advances through the spout to be discharged, and particularly through the avenues between the vane series. The spout revolves at a speed which. allows the vanes to interrupt and retard the advancing material, which effects a tumbling-over action.

By reason of the pitch of the vane, this action forces anything engaged by the vane toward the mill, such as balls, broken parts, and over-size. That part of the discharge which passesover the tops of the vanes continues to the discharge and particularly so when it is relieved from the vanes and joins in the unobstructed avenues between the series. As the material advances, it is caught .by a succeeding vane, which is in advance ofv the last vane which acted upon it, and another tumbling-over action results.

The increasing height of the successive vanes produces an increasingly retarding effect so that, as above pointed out, each succeeding vane produces a submerging action upon the previous vanes, so that difi'erent' vanes act upon difierent depths of the material, and classification results.

The operation of the form of Figs. Sand 7 is similar, as will be apparent.

Variation of the shape and, position of the vanes can be made according to specific conditions. The vanes are preferably cast integral with the discharge spout, being formed with wear-resisting qualities. By

reason of the-position of the vanes, they are so'located that they receive very little if any action from the tumbling mill load; also the different parts, particularly the vanes of increasing height, are so located that each successive part affects the preceding action of the mill.

From the foregoing it will be seen that I have provided a device which will permit of the quick discharge of the load and at the same time retain and return to the mill balls or parts or over-size which would otherwise escape. At the same time the device is very durable and presents a relatively open discharge. It also allows a surcharge of the mill load without materially raising the gradient of the pulp line within the'mill.

I claim:

1. A mill having hollow trunnions, said trunnions being provided with a series of separated internal vanes, said vanes being arranged to act in planes normal to the direction of discharge flow from the mill, so that as said vanes revolve with the mill, they intermittently intercept the mill discharge to return the heavy material to the mill and allow the fines and light material to discharge.

2. A mill having rotary hollow trunnions,

said trunnions being provided with a plurality of internal vanes, the ends of said vanes being arranged to act in planes normal to the direction of discharge from the mill,

so that as said vanes revolve, their ends will intermittently intercept the mill discharge to return the heavy material to the mill and allow the fines and light material to discharge from the mill.

3. A. mill having hollow trunnions, and a discharge spout mounted within one of said trunnions, said spout being provided on its inner surface with a series of separated vanes, said vanes having a pitch adapted to return heavy or coarse parts to the mill.

4. A mill having hollow trunnions, and a discharge spout mounted within one of said trunnions, said spout being provided on its inner surface with vanes, said vanes having a pitch adapted to return heavy or coarse parts to the mill, said vanes being arranged in series with avenues between them.

5. A mill having hollow trunnions, and a discharge spout mounted within one of said trunnions, said spout being provided on its inner surface with vanes, said vanes having a pitch adapted to return heavy or coarse parts to the mill, said vanes being arranged in series with avenues between them, said vanes increasing gradually in height from the feed end to the discharge end of the spout.

6. A mill having hollow trunnions, and a discharge spout mounted within one of said trunnions, said spout being provided on its inner surface with vanes, said vanes having a pitch adapted to return heavy or coarse parts to the mill, said vanes being inclined toward the mill to provide pockets at their parts of the mill, said vanes being inclined bases. toward the mill to provide pockets at their 7. A mill having hollow trunnions, and a bases, said vanes being arranged in series 10 discharge spout mounted Within one of said with avenues between them. 5 trunnions, said spout being provided on its In testimony whereof I affix my signature.

inner surface with vanes, said vanes having a pitch adapted to return heavy or coarse NEWTON L. HALL. 

